A study of the diagnostic accuracy of the PHQ-9 in primary care elderly

BMC Primary Care

Table 3 Receiver operating curve analyses for major depression for each screening instrument

	N*	PHQ-9 AUC^† (95% CI)^‡	PHQ-2 AUC (95% CI)	GDS AUC (95% CI)
Overall	69	0.87 (0.74-1.00)	0.81 (0.65-0.98)	0.81 (0.70-0.91)
Gender
Male	26	0.88 (0.72-1.00)	0.91 (0.78-1.00)	0.76 (0.58-0.93)
Female	43	0.85 (0.61-1.00)	0.70 (0.37-1.00)	0.84 (0.70-0.98)
Race
White	47	0.88 (0.73-1.00)	0.87 (0.75-0.99)	0.85 (0.74-0.95)
Non-white^‡	22	0.93	0.31	0.90
Age
< 80 years	38	0.92 (0.81-1.00)	0.81 (0.54-1.00)	0.82 (0.68-0.96)
≥80 years	31	0.80 (0.52-1.00)	0.83 (0.64-1.00)	0.80 (0.62-0.98)
Comorbidities
< 3	41	0.93 (0.82-1.00)	0.92 (0.85-1.00)	0.79 (0.55-1.00)
≥3	28	0.80 (0.57-1.00)	0.71 (0.43-0.99)	0.82 (0.67-0.97)

* N is for PHQ-9 and PHQ-2; GDS is missing for one participant.
^† AUC = area under the receiver operating characteristic curve. Values range from ≤0.5 (no discriminatory ability) to 1.0 (perfect discrimination -- in this case, of depressed from non-depressed).
^‡ CI = confidence interval.
^§ Only one of the 22 non-white participants had a positive SCID, and therefore no confidence interval could be calculated.

ISSN: 2731-4553